Background: Urea standard Kt/V (stdKt/V) provides a tool to normalize weekly small solute clearance for patients dialysed at various intervals, but it has not been studied in the paediatric haemodialysis (HD) population.
Methods: Using retrospective monthly adequacy data from children with end-stage renal disease receiving chronic thrice-weekly haemodialysis (n = 30), single-pool (spKt/V), equilibrated (eKt/V) and standard Kt/V (stdKt/V) were calculated for each individual HD session. eKt/V was estimated using Goldstein's logarithmic extrapolation method. Standard Kt/V was calculated using Leypoldt's formula based on eKt/V, duration and dialysis frequency. A spKt/V vs stdKt/V dose/frequency table was then derived from our thrice-weekly data.
Results: Using spKt/V of >or=1.2 as the minimal acceptable HD dose, receiver operating characteristic curve analysis was used to determine the corresponding target stdKt/V across a number of potential cutoff values. Single-pool Kt/V >or=1.2 was delivered with near certainty [sensitivity: 93.5%, specificity: 96.7%, area under the curve (AUC): 0.98] when a stdKt/V >or=2.0 was targeted. For a spKt/V >or=1.4, a target of stdKt/V >or=2.2 provided sensitivity and specificity of 73.4 and 96.1%, respectively, with an AUC of 0.94.
Conclusions: Our data demonstrate that one should deliver a stdKt/V >or=2.0 for thrice-weekly paediatric HD in order to achieve a spKt/V >or=1.2; and if one wishes to ensure a spKt/V >or=1.4, then the stdKt/V must be >or=2.2. For children receiving a spKt/V >or=1.6 more than thrice weekly, the currently published adult dose/frequency table will overestimate the stdKt/V dose delivered and should be replaced by paediatric derived values.